I only ask, as if 1D was broken, then E+F would still be useable... 2DEF are totally useless as escape from that full row of seats would be compromised in an evacuation.

The Red Disc is the indication that the row of seats are "Locked" which was more relevant in the good old days of Club Conversion. However, if the incident which broke 1D had enough force, it may have broken the locking mechanism which would explain why 1EF were also blocked out. That was all.

Thanks though!